first off, the SR20DET is a 2.0L, twin cam, turbo four with an aluminum block producing 202hp and ~170ft/lb @5K rpm. the KA24DE is a 2.4L twin cam, NA four with an iron block putting out 155hp & 160ft/lb stock. and, yes, you can make more power on the KA. and easily. of course, to get the power of an SR you'll want a turbo, but
realnissan.com and
nsport.com both have kits available for the KA. both come with a T04 and FMIC though, so you won't need to upgrade them in the future like you will with the SR.